Portable personal computers have become increasingly common and portable workstations are starting to appear on the market. Currently, most workstations operate using some variant of the UNIX.RTM. operating system.
To enable a portable computer to operate on battery power for a significant period of time, some type of power management scheme is required. Some portable personal computers based upon Intel.RTM. microprocessors implement a hardware based power management system called Advanced Power Management. However, there is currently no power management scheme that is compatible with the UNIX.RTM. operating system. Thus, it would be desirable to implement a power management system that is compatible with the UNIX.RTM. operating system such that a power conserving portable workstation can be built.